Use of aerosol pulse parameters as a sensitive discriminator between middle-aged healthy smokers and nonsmokers.

Aerosol particles of about 0.8 μm diameter behave in many respects like a non-diffusing gas and trace almost exactly the mass movement of air during a breathing cycle. By means of an inhalation apparatus which allows continuous monitoring of respiratory volumes and of aerosol concentration, changes of inhaled aerosol pulses during a respiratory cycle were studied. Aerosol pulse parameters (APP) as well as conventional pulmonary function tests (PFT) were evaluated for 32 healthy nonsmokers (NS) and 32 severe smokers (S). APP and PFT were compared to rule out the discriminative potential of the different methods for the detection of early changes of abnormal lung ventilation. Conventional pulmonary function tests of all subjects were within the normal limits. Slight but significant differences between NS and S were found for MEF25 and FRC. In contrast most of the APP showed highly significant differences between NS and S. Therefore it is concluded, that the determination of APP may be more sensitive to detect early changes in pulmonary function tests as bodyplethysmography and spirometry